Science Starter – Label the parts of the Earth and then sit quietly and wait for further instructions. A B C D

Chapter 3, Section 3.1 “Rock Recycling” The Rock Cycle Chapter 3, Section 3.1 “Rock Recycling”

Looking Back Minerals Mineral Properties Mineral Lab

Let’s Review What is the definition of a mineral? What is cleavage? Naturally occurring inorganic solid with a crystalline atomic structure and set chemical composition. What is cleavage? Planes of weakness along which rocks break. Is color alone an effective way to identify a mineral? No, because many minerals have different colorations so it can be misleading/hard to identify minerals based on color alone.

TEST THURSDAY, PLEASE STUDY Looking Ahead Tomorrow we start our 2-day lab of mineral identification and properties. TEST THURSDAY, PLEASE STUDY VOCAB CH 2 QUIZ TUESDAY

PLEASE WRITE DOWN AND DEFINE AS WE GO ALONG! Chapter 3 Vocabulary PLEASE WRITE DOWN AND DEFINE AS WE GO ALONG! Intrusive Igneous Rock Extrusive Igneous Rock Porphyritic Texture Granitic Composition Nonfoliated Metamorphic Rock Hydrothermal Solution Foliated Metamorphic Rock Regional Metamorphism Basaltic Composition Andesitic Composition Ultramafic Erosion Deposition Compaction Cementation Chemical Sedimentary Rock Clastic Sedimentary Rock Contact Metamorphism Rock Igneous Rock Sedimentary Rock Metamorphic Rock Rock Cycle Magma Lava Weathering Sediments Metamorphism

Why do we study rocks? All Earth processes such as volcanic eruptions, mountain building, erosion, and even earthquakes involve rocks and minerals. Rocks contain clues about the environments in which they were formed. If a rock has shell fragments it was probably formed in a shallow ocean environment! The location of volcanic rocks tell a story of the volcanic history of earth through time. Understanding rocks is key to understanding the Earth’s history!

Rocks A rock is any solid mass of mineral or mineral-like matter that occurs naturally as part of our planet. A few rocks are composed only of one mineral, but MOST ROCKS (like granite) occur as solid mixtures of minerals. Each mineral retains its properties in this mixture. A few rocks are made of non-mineral material. Obsidian and Pumice are volcanic rocks that do not have a crystalline structure. Coal is considered a rock even though it consists of organic material. NOTE IT IS A ROCK—NOT A MINERAL!!!

Non-Mineral Rocks

Rocks Classified into three groups based on how they are formed: Igneous Sedimentary Metamorphic Each of these types of rocks is capable of turning into another type under the right conditions!

The Rock Cycle Remember: Earth is a SYSTEM! What is a system, again? Interactions among Earth’s water, air, land, and living things can cause rocks to change from one type to another. The continuous processes that cause rocks to change make up the rock cycle. Most changes in the rock cycle take place over LONG PERIODS OF TIME.

The Rock Cycle

Parts of the Rock Cycle – Magma to Igneous Rock Magma is molten material that forms deep within Earth’s surface. Magma that reaches the surface is called LAVA. When Magma cools and hardens beneath the surface or as the result of a volcanic eruption, igneous rock forms!

Igneous at the Surface What happens to mountains over time? Any rock at the Earth’s surface undergoes weathering. Weathering is a process in which rocks are physically and chemically broken down by water, air, and living things. These weathered pieces are called sediments.

Sediments to Rock So now we’ve got a bunch of weathered rock sediments, what now? The weathered rock moved through erosion and transport. The sediments are deposited, usually at the bottom of an ocean or basin. The sediments start the LITHIFICATION process (they’re turning into rocks) Eventually you have a sedimentary rock!

Rock Changes - Metamorphic Often times sedimentary rocks or igneous rocks end up very deep below the surface. Under the extreme pressure and heat of the Earth, these rocks can change into metamorphic rock! What does ‘meta’ mean? Hint: Metamorphosis If the metamorphic rock continues to be under high pressure and heat it melts to MAGMA and the process starts all over again!

Overview

Alternative Paths This rock cycle is not concrete! It certainly does NOT have to go in order! Example: Igneous Rock remains deeply buried, and can be exposed to heat and pressure and become a metamorphic rock (it does NOT have to be sedimentary first!) Then if the metamorphic rock got hot, it could go right back to being magma! Rocks do not always remain buried, they can often come to the surface and then be weathered away to become sediments! But if sedimentary rock gets buried again it can become metamorphic!

Why does the Rock Cycle Happen? This process takes a lot of energy to work! Where do you think it comes from? Processes driven by the heat from Earth’s interior are responsible for forming both igneous AND metamorphic rocks! The core is very hot, and melts rocks down to magma and can even change rock to metamorphic rock! Weathering and the movement of sediments are external processes. Powered by energy from the sun: Creates weather to chip away at rocks and then transport them. These external processes create SEDIMENTARY ROCKS!

Review What is the difference between magma and lava? Magma is molten rock underground, lava is molten rock at the surface. What is the process that creates sediments? Weathering What driving energy source creates SEDIMENTARY rocks? The sun’s energy What would happen to a rock that started weathering? Sediments would form, sediments would be transported then buried, cemented, and compacted to form sedimentary rock. OR…?